Systems are known in which security of an article is provided by a device that detects one or more events associated with an article being compromised. In particular, articles to which security may be provided include cars, lorries, construction plants, bicycles, luggage, bags, boxes, caravans, trains, tents, portable buildings, intermodal containers, houses, shops, offices, other buildings, and any other similar construction. An article may be compromised if it is removed and/or accessed without authorisation. In particular, a level of protection may be applied to an article/appliance (such as, for example, a lock and/or tether), and breach of that protection (such as, for example, breaking a lock and/or tether) and/or circumvention of that protection (such as, by accessing the appliance via an un-locked route) would constitute the article being compromised. In certain circumstances, a level of protection may not be applied to an article, whereupon the article may be compromised merely by being accessed and/or moved. Known systems may detect breach and/or circumvention of protection applied to an article, or access or movement of an article.
Known security systems issue an audible and/or visible alarm to alert all those local to the article that the article has been compromised. However, for various reasons, passers-by do not respond to such an alarm/alert. For instance, a high frequency of false and/or nuisance alarms encourage passers-by to ignore audible and/or visible alarms. Furthermore, passers-by may not wish to endanger themselves by investigating an alarm/alert. This is particularly important in remote areas where a driver of an alarmed container lorry may not wish to investigate an alarm without support from other people and/or the authorities (such as the police). In addition, known alarms provide no indication to an observer how long they have been triggered. For instance, a home-owner may return home to find their alarm activated, but has not indication of how long the alarm has been triggered, and is therefore unaware of whether intruders are likely to still be present within the house, or whether local authorities are likely to have already responded to the alarm.
The present invention seeks to overcome these problems.